Paper-Handling Installation and Method of Automatically Controlling the Processing Speed Thereof

ABSTRACT

A paper-handling installation is initially set for executing a job to process a predetermined number of articles during a predetermined time period. During the processing, the number of articles detected which are processed during the predetermined time period is detected. If the detected number of articles is larger than or equal to the predetermined number, the speed at which articles are processed in a section of the paper-handling installation will be increased. If the detected number of articles is smaller than the predetermined number, it will be detected which of the sections of the installation caused a reduction of the throughput, and which installation parameters and/or article parameters existed at that point in time. On the basis of the parameters detected, an installation parameter of the section is then set, and/or the speed is reduced in at least that section. This procedure is repeated until the job has been executed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national entry of PCT Patent ApplicationSerial No. PCT/EP2007/010566 filed 5 Dec. 2007, and claims priority toGerman Patent Application No. 102006058219.5 filed on 5 Dec. 2006, whichis incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a method of controlling (or open-loopcontrolling), or regulating (or closed-loop controlling), the processingspeed of a paper-handling installation, wherein articles are moved whileusing at least one transport mechanism, and to a paper-handlinginstallation, the articles being moved individually or in groups in thepaper-handling installation. In particular, the present inventionrelates to a method of automatically controlling the processing speed ofenvelope inserters or letter envelope processing systems andpost-processing systems, and to storing, for re-use, the parametersdetermined by the control.

Conventional technology has known paper-handling installations for whichthere is already the possibility of strongly effecting or controllingspeeds in individual modules—if the system is designed to be modular—orin the entire system. There is a need, for example, to process difficultarticles to be produced, e.g. articles having low paper grammage, smoothsurface finish, heavy inserts or heavy fillers and the like. Toguarantee safe processing within the overall arrangement, it is usefulto reduce or adapt the transport and further processing speeds and/orthe clock cycles at which the individual modules operate. In addition,high efficiency performance of the system is achieved in this manner.Conventionally, this is achieved in the following manners.

-   -   a first, well-known approach consists in simply controlling the        rotational speed of one or several motors in the system or in        the module. As a rule, the control is performed on the        component, i.e. the motor, by directly inputting the parameters.        Such changes may be achieved, for example, via digital input        values, e.g. with servomotors, or by utilizing controllers, for        example slide controllers, e.g. for changing the operating        voltage of the motor. In practice, these are mostly predefined,        fixed settings which may be changed, such a change being made on        the part of the operation personnel, however.    -   a second possibility consists in changing the timing of the        light barriers used in the system or in the module which serve        to detect the presence of an article to be processed. By        adapting the timing, the requirement behavior and the delay        behavior of the handling stations, which operate in a clocked        manner, for transporting the articles is controlled. This        adaptation enables a reduction or extension of the clock cycles,        but does not result in any change in the actual transport speed.        Nevertheless, some kind of controlled speed of the overall        system results as a consequence of the changed clock cycle        values. In this context, too, the values are typically input via        digital values at operating units comprising displays, or at a        central, PC-assisted operating unit, and are typically input by        the operation personnel of the installation.    -   A further possibility that has been known in conventional        technology consists in combining the above-described approaches,        i.e. in combining speed control with adapting the timing. In        this manner, a technical advantage may be achieved over the        above-described, isolated approaches, since because of the        reduced requirement times, the associated speed may usually also        be reduced by means of a corresponding logical function. This        combination is put into practice, within an individual module or        within the overall system, by corresponding control logic, the        control again being performed, however, via inputting        corresponding digital control values at the operating units        having displays or at the central, PC-assisted operating unit,        via sliding controllers and the like, which again is performed        on the part of the operation personnel.

The disadvantages of the above-described approaches are obvious. All ofthe methods do not represent any actual closed-loop control, but, asdefined by control technology, a control with predefined or fixed valueswithout any reset values, target values or the like as defined by aclosed loop control system being taken into account. All of theapproaches actually are open loop control systems wherein the operatoris expected to determine or predefine the optimum settings forprocessing.

In this context, a number of disadvantages result, mention being madehere only of several major disadvantages. There is the questionconcerning the defaults according to which the settings at theinstallations are actually to be performed, in addition, the questionarises where and in which areas of the module or of the system suchsetting actually need to be made, who is responsible for the correctnessof the settings, who actually has access to the setting possibilities,and how these access possibilities are governed. In addition, thequestion arises as to how the benefit may be quantified and specifiedwith regard to the settings which are ideal for the process.

SUMMARY

According to an embodiment, a method of processing articles in apaper-handling installation, the paper-handling installation being set,on the basis of a job description, to process a predetermined number ofarticles during a predetermined time period, may have the steps,performed by the paper-handling installation, of: (a) detecting thenumber of articles being processed by the paper-handling installationduring the predetermined time period; (b) if the detected number ofarticles is larger than or equal to the predetermined number ofarticles: (b.1) increasing the speed at which the articles are processedin at least one section of the paper-handling installation by apredetermined amount of increase, and (b.2) setting the predeterminednumber of articles equal to the detected number of articles; (c) if thedetected number of articles is smaller than the predetermined number ofarticles: (c.1) detecting which of the sections of the paper-handlinginstallation has caused a reduction in throughput during thepredetermined time period, (c.2) determining at least one installationparameter present here and/or at least one article parameter, and (c.3)on the basis of the parameters determined in (c.2), setting at least onesection of the paper-handling installation and/or reducing the speed atwhich the articles are processed in a section of the paper-handlinginstallation, by a predetermined amount of reduction; and (d) repeating(a) to (c) while the job is being processed.

According to another embodiment, a paper-handling installation forprocessing articles which is set on the basis of a job description so asto process a predetermined number of articles during a predeterminedtime period may have: a first sensor for detecting the number ofarticles which are processed by the paper-handling installation duringthe predetermined time period; a second sensor for determining at leastone installation parameter and/or at least one article parameter; and acontrol unit effectively connected to the sensors and configured to,while processing the job, increase the speed at which the articles areprocessed in at least one section of the paper-handling installation, bya predetermined amount of increase, and to set the predetermined numberof articles equal to the detected number of articles if the detectednumber of articles is larger than or equal to the predetermined numberof articles; and detect which of the sections of the paper-handlinginstallation caused, during the predetermined time period, a reductionof the throughput, and, on the basis of the parameters present here, toset at least one installation parameter of at least one section of thepaper-handling installation and/or to reduce the speed at which thearticles are processed in one section of the paper-handling installationby a predetermined amount of reduction if the detected number ofarticles is smaller than the predetermined number of articles.

The present invention provides a method of processing articles in apaper-handling installation, the paper-handling installation being set,on the basis of a job description, to process a predetermined number ofarticles during a predetermined time period or time interval, the methodincluding:

-   -   (a) detecting the number of articles being processed by the        paper-handling installation during the predetermined time period        or time interval;    -   (b) if the detected number of articles is larger than or equal        to the predetermined number of articles:        -   (b.1) increasing the speed at which the articles are            processed in at least one section of the paper-handling            installation by a predetermined amount of increase, and        -   (b.2) setting the predetermined number of articles equal to            the detected number of articles;    -   (c) if the detected number of articles is smaller than the        predetermined number of articles:        -   (c.1) detecting which of the sections of the paper-handling            installation has reduced a reduction in throughput during            the predetermined time period,        -   (c.2) determining at least one installation parameter            present here and/or at least one article parameter, and        -   (c.3) on the basis of the parameters determined in step            (c.2), setting at least one installation parameter of a            section of the paper-handling installation and/or reducing            the speed at which the articles are processed in a section            of the paper-handling installation, by a predetermined            amount of reduction; and    -   d) repeating the steps (a) to (d) while the job is being        processed.

The present invention further provides a paper-handling installation forprocessing articles which operates in accordance with the inventivemethod.

The object set forth above is achieved by turning the open-loop controlinto closed-loop control for controlling a paper-handling system or amodule of a paper-handling system. Turning the open-loop control intoclosed-loop control ensures, on the one hand, that by the module or thesystem independently determining, setting and storing the optimumparameters, maximum effective performance may be achieved, duringdeployment operation, from job to job using different materials. On theother hand, the possible influence exerted by the operator on theoverall performance of the module or of the system is reduced, while atthe same time the overall operability and the overall operation effortis reduced without entailing a loss of control of the overallprocessing, including the possibility of monitoring the processes.

The inventive approach avoids the previous, conventional procedurewherein adaptation in subareas of the individual processes, e.g. withinthe module or within the system, was possible, however without anyautomatic correction. In accordance with the invention, tedious trials(trial-and-error operations) and, consequently, the time and stressdemanded of the operation personnel by this, are thus avoided. Theparameter changes in processing which were performed on the part of theoperation personnel were indeed useful and helpful, but the inventiveapproach represents a clearly more effective procedure as compared tosaid approaches which were implemented as open loop control systems. Dueto the automatic, system-inherent identification of the parameters onthe part of the module/system in dependence on the job to be processed,a controlled speed, or a controlled clock is determined in a faster,more reliable and permanently repeatable manner without this dependingon the capabilities of the operation personnel.

In accordance with the invention, a reduction of stops, which representa potential cause for damage to the articles or even destruction of thearticles, a reduction of wear and tear, extension of the applicationspectrum is achieved for an optimum speed of the processing within themodule/system at a maximum effectiveness, independently of anyintervention on the part of an operator.

In accordance with the invention, the entire system may autonomouslycontrol itself, wherein advantageously all accesses to the respectiveparameters, be it at the operating units or at a central, PC-assistedoperating unit, are accessible only to the maintenance personnel, i.e.not the operation personnel, the respective areas being protected, inaccordance with an advantageous embodiment, by corresponding encryption.

In particular, repeated performance of the same job is improved bystoring the results of the settings, since parameters which have alreadybeen obtained during operation (and which were essentially optimumparameters at the time of the latest performance of the job) now existas the starting point. Starting from said existing parameters, theinstallation may now be set for repeated performance of the job. Theoptimum speeds and optimum clocks determined during a job are logged andmade available again as parameters for each individual component whenthe job stored is called up again, corresponding autonomous controlsetting itself during operation if the job is defined differently. Theadvantage of this approach is that the system may be placed in aninitial state for processing the job, of which initial state one knowsthat the installation for the planned articles operates, in principle,at a high effectiveness with the parameters already determined.

Administration of these job parameters may evidently also be transferredfrom one system to another system while using a superordinated storagelocation, and/or may be taken into account in central job preparation. Afurther implementation consists in selecting the best-suited system forprocessing a specific job on the basis of the parameters, which havebeen determined and controlled, for adapting the speed and clock. Ofcourse, this adaptation may also be logged in the central operatingsystem and be used for further analyses, and it may therefore bemonitored.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be detailed subsequentlyreferring to the appended drawings, in which:

FIG. 1A-1C show flowcharts of an advantageous embodiment for setting thespeed at which articles are processed in a paper-handling installation;

FIG. 2 shows a flowchart of an advantageous embodiment of the inventivemethod, wherein the degree of deviation of the detected parameters istaken into account in successive time intervals;

FIG. 3 shows a further advantageous embodiment of the inventive methodwherein the degree to which the numbers of defects differ in successiveintervals is taken into account to cause or not to cause, as a functionthereof, a change in the settings of the installation.

FIG. 4 shows an isometric representation of an inventive paper-handlingsystem in accordance with an embodiment described by means of anenvelope inserter; and

FIG. 5 shows a block diagram depicting communication of informationbetween the central controller and the portions of the envelope inserterof FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

In the description which follows, advantageous embodiments of thepresent invention will be explained in more detail, the same referencenumerals being used for the same or similar elements. It shall be notedthat the description which follows merely represents an advantageousembodiment of the present invention, but that the invention is notlimited to this specific implementation. In addition, the term“plurality” will be used in the description which follows, which term isto be understood as meaning two or more in the context of the presentinvention.

The present invention may be employed wherever paper is machined withina system and ends up being fed either to a storage location and/orfurther processing system, or is inserted, along with supplements, orinserts, or enclosures, into an envelope and then is stored and/orsubjected to after-treatment. For example, the paper is fed from a stackor from a roller in an endless manner or as individual sheets.Processing within the system comprises, for example, separating,folding, collating, deflecting and similar paper processing steps.Generally, the present invention may be applied to any semi- andfull-automatic paper processing systems serving the purpose of sendingor passing on information. The present invention is not limited toenveloping systems, but may also be employed in envelope sorting lines,e.g. sorters, or in mail distribution systems. In addition, theinventive approach may be applied both to individual modules within asystem and to a system as a compound structure.

The inventive approach utilizes a plurality of parameters including,e.g., installation parameters, environmental parameters and articleparameters. These parameters are used for enabling closed-loop controlof the installation, which will be described in detail below.

The installation parameters comprise parameters which relate to thesetting of individual components within the installation or of one ofseveral components within the installation as well as their wear andtear. For example, the installation parameters relate to the followingcomponents of a paper-handling installation:

-   -   for the transport elements employed in the installation, e.g.        for the rollers, the belt or vacuum conveyors: the roller or        belt pitch and the intake pressure; for lateral guides: the        position/the pitch of the guide elements; for a lock chamber:        the roller pitch; or for nozzles: the amount and time of supply        of blow air;    -   for the driving elements used in the installation, e.g. for the        motors: the rotational speed of the transport motors, and the        acceleration of the articles by the driving elements;    -   for the functional components employed in the installation: e.g.        the take-up speed and the acceleration of the articles, and in        addition, for example for a collating station: a meter reading        indicating the collation quantity, and the weight of the group        collated; for sheet feeders: the filling level; for an envelope        inserter: the filling speed; for an output path: the filling        quantity.

The parameter values are detected via sensors provided in theinstallation accordingly, and/or are obtained from the position ofservomotors provided for adjusting various elements (e.g. servomotorsfor the rollers, guide elements, etc.)

Additionally, information on the state of the installation, e.g. on thewear-and-tear state of individual elements (e.g. wearout of thetransport rollers or belts used) within the installation is detected.

The environmental parameters relate to, for example, environmentalfactors, e.g. temperature, humidity, static charge, etc. The values ofthe environmental parameters are also detected centrally and/or atimportant locations within the installation by suitable sensors.

The article parameters comprise the physical nature of the articles tobe processed, such as of the paper to be processed, of inserts to beprocessed, and of envelopes to be processed, for example the weight ofthe article, the size of the article, the dimensions of the article, thenature of the material of the article, the basis weight of the article,the flexural strength of the article, the coefficient of friction of thearticle, the air permeability of the article, the roughness of thearticle, and the thickness of the article. These parameters, too, aremonitored by suitable sensors within the installation.

It shall be noted that the above listing of the potential parameters isonly exemplary, but not exhaustive.

In addition, a job description is provided which in addition to theindications on the settings of the various parameters of theinstallation also contains supplementary information on the articles tobe processed. For example, a job description contains the number of thearticles to be produced in the entire job, the number of the articleswhich may be contained in each group, the indication of the feeders fromwhich the articles are to be fed and combined into a group, etc. Inaddition, the job description contains information on the height and thewidth of the article to be processed, on the initial transport speed inthe various sections of the installation, for example at the inlet, atthe outlet, for example for a potential transverse transport, etc.

Depending on the conditions, a job description contains furtherindications known to experts, in principle. Said job description iselectronically provided, to the paper-handling installation, for examplein the form of a file, either by transmission via a network or byreading in the file from a data carrier.

Advantageous embodiments of the inventive method will be explained belowin more detail with reference to FIGS. 1 to 3.

FIG. 1 shows a flowchart depicting an advantageous embodiment of theinventive method. The method starts at step S100, which comprisesprocessing articles in a paper-handling installation starting from aninitial state. In this context, the paper-handling installation has beenset on the basis of a job description, the job description alsoindicating a predetermined number of articles to be processed during apredetermined time interval or time period. Once the paper-handlinginstallation has been set and the articles to be merged have beenprovided at the various inlet points of the installation, theinstallation starts to process the job.

The inventive method is provided to control the processing of thearticles such that a maximally possible number of articles processedduring a predetermined time period is yielded (maximum throughput).

Step S102 comprises detecting, during the predetermined time period, forexample during a specified time unit of several minutes of severalhours, the number of articles processed during this time period. StepS104 comprises determining whether the number of articles actuallyprocessed is larger than or equal to the predetermined number ofarticles. If it is established that the number of articles exceeds thepredetermined number, the method proceeds to step S106 (see FIG. 1B).Said step comprises increasing the speed at which articles are processedin at least one section of the paper-handling installation by apredetermined amount of increase, and step S108 comprises setting thepreviously detected new number equal to the predetermined number, andstep S110 comprises storing the parameters and speed which have now beenset for future use. In other words, it is recognized that theinstallation operates reliably with the current settings, so that inaccordance with the invention, the processing speed is increased,wherein monitoring is performed, as will be described in detail below,as to whether the increase in the processing speed results in anincrease in the throughput. In accordance with the invention, theinstallation is thus controlled so as to achieve as high a throughput(number of articles processed per predefined time period) as possible.

Subsequently, the method proceeds to step S112 (see FIG. 1C), whichcomprises determining whether the job has been completed. If this is so,the method will end at step S114. If the job has not yet been completed,the method will return to step S102.

If it is established, in step S104, that the number of articles to beprocessed within the time period is lower than the expected orpredetermined number (with or without previous increase), the methodwill proceed to step S116.

The drop in the number of articles as compared to the predeterminednumber is due to the fact that during processing of the articles in thepaper-handling installation a defect has occurred at one or severallocations, said defect usually leading to a preliminary stop(interruption of the processing) of the installation until the defecthas been remedied, for example by the intervention of an operator.Likewise, the number of articles to be processed will be reduced if anygroups of articles which have been collated within the installation aredefective, for example if the wrong inserts or a wrong number of insertshave been added to a letter. In this case, said defective articles willbe removed from the installation, which entails a correspondingreduction of the throughput.

As defined by the present invention, a defect is understood to beanything which results in a reduction of the throughput of articlesprocessed, i.e., for example, an interruption of the processing ormanufacturing of defective articles.

In this case, step S116 comprises examining at which point in thepaper-handling installation a defect has occurred during the time periodcontemplated. Subsequently, step S118 comprises determining, for thisarea of the installation, at least one state or value of an installationparameter and/or an article parameter which existed while the defectoccurred and which, as a rule, caused the occurrence of the defect. Forexample, a mechanical component within the installation may havemisadjusted, so that re-adjustment may be performed, or the propertiesof the article to be processed have changed. All of these factors bythemselves, respectively, or in combination may have led to theoccurrence of the defect.

Depending on which installation parameters and/or article parametersexisted at the time of the occurrence of the defect, step S120 comprisessetting at least one installation parameter within a section of thepaper-handling installation. In addition or alternatively, the speed atwhich the articles are processed in the respective section of thepaper-handling installation may also be reduced by a predeterminedamount of reduction, as is also depicted in step S120. For example, ifit is established that the installation parameters and/or articleparameters had not changed, when the defect occurred, as compared toprevious parameters/article parameters, it may be assumed that thetransport speed resulted in the occurrence of the defect, and in thiscase, said transport speed will be lowered. As was mentioned above, thismay either be performed by itself or along with setting other parametersof the installation.

If it is found that a property of the parameter of the article to beprocessed, for example the roughness of the paper, is changing, it willbe sufficient, for example, to change the contact pressure of thetransport drums within the affected section of the paper installationwithout a change in the speed being necessary. However, if it isadditionally found that the thickness of the paper has also changed, sothat said paper can no longer be moved at the original speed, thetransport speed may also be changed. For example, if only the thicknessof the paper has changed, it might be sufficient to change the speedonly. Setting the speed within the installation is performed, forexample, by changing a rotational speed of a motor, by changing anacceleration of articles within the paper-handling installation, and/orby changing the clock performance. Advantageously, the change isperformed step by step, or in stages (incrementally).

Once the installation has been reset in step S120, the method proceedsto step 112 in FIG. 1C, which comprises checking whether the job hasbeen completed. If this is not so, the method returns to step S102, aswas mentioned above. As was mentioned above, the parameters set arestored, which additionally opens up the possibility of creating a logwith regard to the settings during processing of the job. The settingsstored in step S110 may further be associated with the job file, so thatsaid settings may be utilized, during repeated performance of the job,for initially setting the installation, so that the installation may beautomatically set to the corresponding values at a later point in timewhen processing a corresponding job, which may be accomplished, forexample, by controlling corresponding servomotors which cause the changein the transport elements. During repeated performance of the job at alater point in time, the stored data set is initially loaded, andinitial setting of the paper-handling installation is effected, whilere-adjustment is then performed in accordance with the invention,depending on the current state of the installation, on currentenvironmental parameters and while taking into account any potentialvariations in the properties of the article to be processed. In thismanner, in accordance with the invention, fast initial setting of thepaper-handling installation to jobs which have already been performedonce or several times is enabled, and at the same time, automaticcontrol/adjustment of the installation is enabled so to offset anydifferences in the articles to be processed and/or changes in theinstallation and environmental parameters as compared to the initialparameters.

In accordance with the invention, the processing speed within thepaper-handling installation is thus controlled, an increase in theprocessing speed being generally conducted, as long as no defects occur,so as to achieve optimum throughput within the installation.Advantageously, the speed is set such that the speed does not exceed orfall below predetermined maximum and predetermined minimum speeds,respectively. In other words, a “window” is predefined for theinstallation and/or for components or modules of the installation,respectively, said window indicating the upper and/or lower limits ofthe potential speeds. For example, a merger shall be contemplated whichreceives two sheets in parallel and conveys them along a travel pathsuch that the sheets will be arranged one above the other at the end ofthe travel path. For some merger types, the sheets are moved along thistravel path without being driven, so that a predetermined speed of thesheets may not be fallen below while they are being fed to the travelpath, so as to ensure that the sheets will reach the end of the travelpath. Likewise, an upper limit is specified above which the sheets willbe damaged. Both the upper and lower limits depend, among other things,on the paper and/or on its properties (parameters, see above).

With reference to FIGS. 2 and 3, two further advantageous embodiments ofthe present invention will be explained below which introduce thresholdvalues with regard to the deviations of the parameters and/or withregard to the number of defects occurring during a time interval,decisions being made, depending on said threshold values, as to whetherthe changes are severe enough for settings of the installation to haveto be changed, or whether said changes are within acceptable toleranceranges.

In accordance with the embodiment of the present invention which isshown in FIG. 2, step S130 comprises determining a deviation of thedetected parameters as compared to those parameters which were detectedduring a preceding interval or during a preceding time period. In stepS132, said deviation is compared to a predetermined threshold. If thethreshold is exceeded, step S134 comprises setting the installationparameter and/or reducing the speed. If the threshold is not exceeded,the setting of the paper-handling installation in maintained unchanged(see step S136).

In a further embodiment, shown in FIG. 3, of the present invention, stepS140 comprises detecting a number of the defects which occurred duringthe time period or time interval, and step S142 comprises detecting adeviation of the number of defects detected as compared to a precedingtime period or interval. Step S144 comprises comparing the deviationwith a predetermined threshold, and if the threshold is exceeded, stepS146 comprises changing the setting of an installation parameter and/orreducing the speed. If the threshold is not exceeded, the setting of theinstallation is maintained (see step S136).

Within the context of the above description of an advantageousembodiment of the inventive method, a description was given to theeffect that in connection with the setting of the installationparameters and/or the reduction of the speed, the installationparameters or article parameters which exist during the time instant ofa defect are taken into account. In accordance with a furtheradvantageous embodiment of the present invention, it is also possible toadditionally take into account one or several of the above-describedenvironmental parameters. Likewise, the wear and tear of individualelements within the paper-handling installation may also be taken intoaccount. The environmental parameters and/or wear-and-tear parameterswhich have just been mentioned are either continuously monitored or aremonitored at a time instant during the time interval contemplated, orare monitored once during a plurality of time intervals. If theenvironmental parameters and/or the wear and tear are taken intoaccount, the installation is advantageously set while accessing alook-up table wherein corresponding optimum installation parameters arestored for various environmental parameters or for various signs of wearand tear, so that the installation may be reset, e.g. as a function ofan environmental temperature, from an initial temperature rangecomprising a first setting to a second temperature range comprising asecond setting of the installation parameters.

In accordance with a further embodiment of the present invention it isprovided that it is determined, depending on the detected wear and tearof an element, whether or not interruption of the job execution in orderto replace the component exhibiting the wear and tear is useful. This isdetermined as a function of a possible throughput of the paper-handlinginstallation for the job. For example, a situation may arise when thereis the possibility of continuing to operate the installation despitedetected wear and tear of a component, but of operating it at reducedspeed. In this case a decision is made as to whether execution of thejob at the reduced speed is occurs faster than is the case when theinstallation is stopped, the worn element is replaced, and theinstallation is operated again at full speed. By way of example, wearoutof a cutter shall be contemplated here, wherein in this context,replacement of a knife would take two hours. If it is determined thatwithin this time period, the job may be executed at reduced speed whileyielding an equally good result, a decision will be made thatreplacement of the worn element will be put off until an idle phaseafter the job has been terminated, so as first to finish processing thejob being executed. Advantageously, a look-up table is accessed for thispurpose, from which look-up table the amount of time taken to replace anelement may be derived, so that the inventive method determines, on thebasis of the job description from which the number of articles which areto be processed in the overall job is known, determines whether the jobis to be interrupted or is to be completed at reduced speed.

In accordance with a further embodiment, the operation personnel is alsotaken into account. The operators of the installation are equipped withtransponders to detect the number of operators and their positions. Thisallows adjusting a capacity utilization of the paper-handlinginstallation as a function of the number of operators. If the number ofoperators is not sufficient, for example, for regularly placing insertsat the supplement feeders, or for regularly removing the finishedarticles from the output belt, this will lead to an interruption (astoppage) of the installation (defect), which in turn will result in adecrease in the throughput. By monitoring the number of operators it isestablished whether or not there are a sufficient number of personspresent for allowing continuous operation at full capacity. If thenumber of operators is not sufficient, the processing speed will bereduced accordingly, which, however, will lead to increased throughputoverall due to the lack of interruptions occurring on account of insertfeeders running empty or of the storage belt filling up.

Irrespective of the number of operators, one may further monitor in thisembodiment, in accordance with the invention, whether any defects haveoccurred during the operation without the set parameters having changedduring successive time intervals. It is possible to detect, along withthe information on the number of operators and the positions of theoperators, that at installation sections, defects occur which call forintervention of an operating person, so that it may be established thatthe installation speed may be reduced for proper handling on the part ofthe operator. When it is detected that the number of operating personshas increased, the speed may be increased again.

In addition, the inventive approach also allows sensing an activity ofthe operating person on the basis of their movements, so as tocommunicate, for example, that a frequently occurring interruption isnot an installation defect, but is due to the fact that the operatingperson has not added further inserts, or enclosures, fast enough or hasremoved completed articles from the output belt.

As was already briefly mentioned above, the articles are processedeither individually or in groups in the paper-handling installation, andin the latter case, the article parameters further comprise the totalnumber of articles within a group. However, it shall be noted, in thiscontext, that it is not mandatory for each group to comprise the samenumber of articles, but depending on the job description, differentgroups will contain different amounts of articles. In this case, avariation in the number of articles (groups) output does not necessarilyrepresent a reduction in the throughput which is to be traced back to adefect. Depending on the size of the group, the duration of compilingthe group up to the group being output varies. If, for example, onlygroups of five elements (letter, enclosures, etc.) are being processedduring the time interval, the throughput will be higher than if groupsof ten elements are processed during the same time interval.

This situation is taken into account in that values are provided for thegroups which indicate the average time period useful for generating thegroups, so that the “predetermined number” of articles (here groups)processed during a time interval, said “predetermined number” being usedfor inventive control, is determined on the basis of said values.

So far, the inventive method has been described by means of aninstallation which is already in operation. Before the inventive controlsets in, the paper-handling installation is initially set for processingthe job to be performed. To this end, the job description (see above) isadvantageously obtained which describes the initial setting of theinstallation parameters for the job to be processed. In accordance withthe installation parameters obtained, the installation is then set(configured). At this stage, an environmental parameter (see above) mayalso be detected, so that the set paper-handling installation may bereset on the basis of this environmental parameter detected. Inaddition, a sign of wear of the paper-handling installation may berecognized, which is useful when the installation has executed one orseveral other jobs since the latest job execution, which possibly led towear and tear of individual parts. In this case, too, resetting of thepaper-handling installation is performed on the basis of the detectedsign of wear.

During the operation of the installation, monitoring of theenvironmental parameters and/or of the signs of wear may be continuouslyperformed in addition to the control as was previously described, so asto allow, irrespective of the throughput, a reaction to said changedparameters in that the paper-handling installation is reset on the basisof the detected parameter values. In addition, the installationparameters and the article parameters may also be continuously monitoredduring operation so as to automatically reset the installation in caseof any deviations, in this case the parameters being detected, as wasalready mentioned, either continuously or at specific fixed points intime during one or several intervals.

So far, a paper-handling installation has been described which comprisesseveral sections, for example a feeder, a collating station, an envelopeinserter, etc., as will be described in detail below with reference toFIG. 4. However, in accordance with the invention, the present methodmay also be applied to paper-handling installations of modular designs,in which case, depending on the circumstances detected, the speed is setin one or more of the modules. Likewise, the parameters may be set inone or more of the modules, in case of a modular design the modulesadvantageously effecting control in a decentralized manner, and only theinterface between the modules being monitored by a central controller.In addition, it may be determined, in an advantageous embodiment,whether following an increase in the speed, a defect has occurred inseveral of the modules or in only one of the modules, so that dependingon this, the speed is decreased either in all or in some of the modulesor only in the module in question.

FIG. 4 shows a paper-handling installation, which is controlled inaccordance with the invention, by way of example of an envelopinginstallation. Such a paper-handling installation comprises a supplychannel comprising, for example, cutters and sheet feeders. The supplychannel is followed by an input channel/processing channel, whereinarticles are collated, folded and gathered. A gathering path provided inthe input channel/processing channel comprises one or more insertfeeders, for example. The input channel/processing channel is followedby the envelope filling, in this context an envelope inserter comprisingan envelope feeder, for example, which provides the envelopes. Theenvelope inserter is followed by post-processing, for example output ofthe enveloped articles to a post-processing system, for example a sorterand the like.

The enveloping installation 100 comprises a first input 102, a secondinput 104, and a third input 106, continuous webs 108, 110, 112, whichare printed for dual-use, being provided at all of the inputs 102 to106, respectively. All of the inputs 102, 104, 106 for continuousprocessing comprise a cutting device not shown in FIG. 4 for cutting thesupplied paper web transversely, on the one hand, and longitudinally, onthe other hand, so as to generate the individual articles to beprocessed.

The first input 102 is followed by a merger or merger path 114, which isfollowed by a collating station 116 wherein a predetermined number ofarticles are collated and are moved further along as a group. Thecollating station 116 is followed by a folding unit 118 and a transportmodule 120.

The second input 104 provides the paper web 110, which is printed fordual-use, and also comprises, just like the input 102, a device fortransversally and longitudinally cutting the paper web 110. In contrastto the first input 102, the second input 104 comprises initially furtherprocessing the cut documents in parallel, in a folding unit 122, whichis followed by a deflection station 124 wherein the folded articleswhich are now placed one behind the other are together transferred to acollating station 126, and from there to a transport module 128.

The articles provided by the transport modules 120 and 128 are collatedin a collating station 129 and are supplied to a further collatingstation 132 via the transport module 130.

The third input 106 represents the continuous paper web 112, which isprinted for dual-use, so that just like the inputs 102 and 104, theinput 106, too, comprises a means for transversely and longitudinallycutting the paper web 112. Similarly to the input 104, the cut articlesare provided in parallel to a folding unit 134 and from there to adeflection means 136, from which the articles, which are now placed onebehind the other, are provided to a collating station 138. Starting fromthe collating station 138, the articles collated there are supplied, viathe transport module 140, to the collating station 132, where they aremerged with the articles provided from the inputs 102. Starting from thecollating station 132, the articles collated are provided to the feeders142 a and 142 b, where optionally further inserts may be added to thestacks of articles formed in the collating station 132. Finally, thearticles, or groups of articles, thus formed are provided to theenvelope inserter 144, which inserts them into corresponding envelopesand deposits the envelopes on a shingled belt 146.

In addition, FIG. 4 shows the central controller 148 of the installation100, the connection of said controller 148 to the modules beingschematically depicted at 148 a. Also, a sensor 150 is shown which isalso connected to the central controller 148, as is schematically shownat 148 b. In the embodiment shown, the controller 148 is realized, forexample, by a computer, possibilities of setting the operation of theinstallation, and the data processing means for logging the documents tobe processed being included, at the same time, via a user interface. Thecontroller 148 further monitors the functioning of the individualmodules and of the overall system, for example for detecting faultconditions.

The system described in FIG. 4 is an enveloping system, for example, asis mainly used for banks and insurance companies, for example for usinginsurance policy documents which are printed for single use or for dualuse. As has already been mentioned, the system comprises three inputs102, 104, 106 for continuous processing, each with collating and foldingpossibilities, as well as a folding insert feeder 142 a comprising barcode readout for intelligent individual-sheet processing. The systemenables merging documents or articles from all of the inputs 102 to 106.The vertical stack belt 146 allows a large storage volume and,consequently, reduced expenditure in terms of operation personnel.

In addition, at important measuring points such as at the inputs 102,104, 106, for example at all of the or at selected processing elements,namely at the collating stations 116, 126, 128, 132, 138, at the feeders142 a and 142 b, at the envelope inserter 144, and at the storagelocation 146, the enveloping installation 100 shown in FIG. 4 comprisessensors S₁ and S₂, which, in accordance with the embodiment described byFIG. 4, detect the nature of the material of the article to be processedwhich is present at the corresponding station, as well as furtherproperties, such as the number of sheets within a group at thecorresponding collating stations. On the one hand, this information isserially transferred, in a so-called “handshake” operation, between theindividual elements of the modular arrangement shown in FIG. 4, and isfurther transmitted, for actively controlling the overall system, to thecentral controller 148. In addition, one or more of the modules shown inFIG. 4 may comprise sensors S₁, which detect wear and tear of thecomponents used, and may also communicate via the overall system and tothe central controller 148 for evaluation. In addition, FIG. 4 may alsoshow the sensor 150, which has already been mentioned and which mayserve to detect environmental parameters, such as the temperature and/orhumidity, the information obtained by the sensor 150 also being providedto the controller 148.

Alternatively or additionally, sensors for detecting the environmentalparameters may also be provided within the individual modules, which isuseful particularly for large installations, since due to the largespatial expansion of such installations, central detection of theenvironmental parameters would not be accurate enough. In the embodimentshown, the sensor S₂ associated with the storage location 146 isprovided so as to supply a signal, on the basis of which the controlunit 148 will determine the actual output performance.

FIG. 4 further shows operators 160A, 160B, each of which is equippedwith a transponder T. The control unit 148 communicates with thetransponders T to detect the number of operators 160A, 160B and theirpositions. Depending on the number of operators 160A, 160B, the controlunit 148 may set the capacity utilization of the paper-handlinginstallation 100, as was described above.

During operation, the installation shown in FIG. 4 operates in theabove-described manner, such that the corresponding sensor signals areoutput to the central controller 148 via the above-described sensors S₁,S₂. In an advantageous embodiment, the central controller 148 obtains ajob description for the job to be processed, as was described above. Onthe basis of the information stored in said job, in conjunction with theproperties detected, the central controller 148 causes the correspondingmodules to be controlled so that they be set. In accordance with anotheradvantageous embodiment of the present invention, the central controller148 falls back on stored parameters with regard to the speeds set whichwere already detected in preceding runs, and on account of the sensorsignals detected it causes suitable post-control for the process to beperformed at that particular point in time.

Examples of the inventive approach will be explained below withreference to FIG. 4.

One example of detecting properties of the article to be processedcomprises detecting a code provided on the paper web, said code beingdetected by a reader in the input channels 102, 104 and 106. Suchreaders are designed, for example, to read the code from the paper webwhile said paper web is passed along the read head at, e.g., 5 m/s. Witha correctly printed code, the read head is able, at said speed, tocorrectly detect the code. However, there may be situations when thecode on the paper web is only poorly legible, be it that it is partlycovered by other features or imprints due to a malfunction in theprevious processing operation, that too little toner was applied, orthat only little contrast exists. In this case, read errors aredetected, since a read operation now is no longer possible at the speedmentioned. An increase in the number of read errors indicates a poorlyprinted code, so that the installation is operative to reduce the“reading rate”, i.e. the speed of the paper web at which the code ispassed along the read head, once a specific threshold of the number ofread errors is reached. The speed may be reduced to 3 m/s, for example,either in one step or gradually, until the read error rate is below thethreshold mentioned. In addition, if the threshold is fallen below,signaling may be generated in order to generate a message whichindicates that the code is only poorly legible.

If the installation is a so-called online installation, i.e. if thepapers to be processed are directly generated by an upstream high-speedprinter, a return channel may optionally be produced between theinstallation shown in FIG. 4 and the associated online printers, so asto control said online printers—in the event that a poorly printed codeis detected—to improve the print of the code.

Even though the above example concerning code detection was described inthe context of the input channels 102, 104 and 106, this embodiment mayalso be employed at any other location within the installation at whicha code is detected.

Optionally, provision may be made for an alert message to be output tothe operator once the speed has been reduced because the thresholdconcerning the read errors has been fallen below, so that said operatormay possibly take steps to counteract said tendency with regard to thepoorly printed code. If the quality of the code continuous todeteriorate, or if the code still cannot be read even though the speedhas been reduced, an error message will be output once a furtherthreshold has been reached, and processing will be stopped.

In a further example, the installation comprises several sheet feeders,and it is found that the defects can be traced back to the fact that afeeder has been depleted. For example, the arrangement shown in FIG. 4comprises three feeders 142 a, 142 b, a first job withdrawing sheetsfrom all of the sheet feeders, for example. As a result, the individualsheet feeders are depleted in a relatively uniform manner, so that as arule, refilling is possible without any problems. However, if a job isperformed wherein only one of the sheet feeders is used, said sheetfeeder will be depleted relatively fast, so that an operator maypossibly not be able to keep up with refilling it, which will makeitself felt by an increased number of interruptions. The installationmay be automatically configured to reduce the processing speed and/or tosuggest an alternative operating mode, for example toggle mode, to theoperator, said toggle mode comprising the use two of the sheet feeders,from which sheets are alternatively withdrawn, so that an operator willhave sufficient time for refilling the installations.

The above description of the advantageous embodiments was based on theoverall system shown in FIG. 4, but those skilled in the art will alsoknow further systems comprising other modules than those shown in FIG.4, and the principles of the present invention may naturally also bereadily transferred to other such modules as will be mentioned belowwith reference to FIG. 5.

FIG. 5 shows a block diagram which illustrates communication ofinformation between the central controller 148 and the individualstations of a paper-processing system as is shown, for example, withreference to FIG. 4. In this case, the individual blocks in FIG. 5 havethe corresponding reference numerals of the modules shown in FIG. 4associated with them, and the filled-in horizontal arrows indicate thecommunication along the installation in the “handshake operation”, andthe non-filled-in vertical arrows indicate the status and situationmessages for active control which are exchanged between the centralcontroller 148 and the individual modules.

As may be seen, the system controller or system regulator 148 containsdefault actuating variables for the individual modules, which initiallyset, for example, the motor speed and the clock cycle of individualmodules so as to provide a defined starting point for processing a job.As an alternative to such actuating variables, which are set, forexample, by an operator, optimum operating points which were determinedin preceding runs may be read out from a memory so as to set the overallinstallation in accordance with the known parameters. As was describedabove, the useful setting may also be derived on the basis ofinformation from job programming and/or from correspondingspecifications of a job.

The four processing channels shown in FIG. 5 comprise, on the one hand,the so-called supply channel 160, the processing channel 162, thefinishing channel 164, and the post-processing channel 166. As wasmentioned above, the respective channels have the corresponding modulesof the exemplary enveloping system 100 of FIG. 4 associated with them,and the supply channel also has so-called autoloaders, dispensers andprinters associated with it in addition to the cutters 102, 104, 106 andsheet feeders 142 a and 142 b, which are shown in FIG. 4. In addition tothe collating stations 116, 126, 128, 132, 136 shown in FIG. 4, to thefolding units 118, 122, 134 shown in FIG. 4, and the deflection means124 and 136 shown in FIG. 4, the processing channel 162 also has rotarymeans, stapling means and the like associated with it. In addition tothe envelope inserter 144 shown in FIG. 4, the finishing channel 164also has stackers and sorters and similar elements associated with it.In addition to the storage location 146 shown in FIG. 4, thepost-processing channel also has franking means, printers, readers,sorters, packaging means and the like associated with it.

In all of the channels, environmental parameters, article parameters andinstallation parameters are detected. Even though with reference to FIG.4, a paper-handling installation in accordance with the presentinvention was described by means of an enveloping system of a modulardesign, it shall be noted at this point that the inventive apparatus isnot limited to modular systems. Likewise, the inventive approach may beapplied to a non-modular paper-handling installation comprising one ormore paper-handling stations. For example, the inventive approach mayalso be applied only in conjunction with the envelope inserter 144 shownin FIG. 4, or with a subset of the modules shown, in which case theenvelope inserter 144 will receive only the articles to be enveloped,and will envelope and output same. In addition, it shall be noted thatthe inventive paper-handling installation is not limited to theenveloping installation shown in FIG. 4. The inventive approach may alsobe employed for other installations having other configurations, itbeing possible for such installations to comprise additionalautoloaders, dispensers, printers, rotary means, staplers, sorters,franking units, packaging means, etc.

In addition it shall be noted that the embodiment described withreference to FIG. 4 comprises sensors, respectively, at theabove-indicated elements of the respective channels, it also beingpossible, however, for the sensors to be provided either at all of theindividual modules or only at selected individual modules, possibly atless than the above-described modules, depending on the conditions ofthe installation.

As was described above, the inventive method may be applied to anoverall installation, to parts of an installation, or to individualmodules of a modularly designed installation, the individual sections ormodules of the overall installation being controlled via a centralcontroller in each case. In accordance with the present invention,individual selected sections or modules, which are particularly criticalto the processing of the articles, are monitored, and their speeds arecontrolled, but provision may also be made for monitoring andcontrolling each individual section or module.

The present invention is not limited to the above-described embodiments,but may be applied wherever paper is machined within a system and iseventually fed to a storage location and/or further-processing means,for example, and it therefore generally relates to any semi- orfull-automatic paper processing systems.

In the description of the embodiments of the invention, any reduction ofthe throughput of articles processed which is due to an interruption ofthe processing or to the generation of defective articles has beenregarded as a defect, as have the events underlying the interruption ofthe processing and/or the generation of defective articles.

In addition to events caused by a malfunction of the installation or ofone or more modules of the installation, one may also consider otherevents, for example the case that all of the modules of an installationper se are properly set, but that one or more of the modules aremodified, for example with regard to their processing speeds, such thatmodules which directly follow them or are further downstream from themwill refuse to take on the articles for processing, since the articlesare supplied too fast, for example (for example, a folding unit mayaccept articles, e.g. paper, only at a maximum speed to ensure properfolding). In this case (event), the articles are no longer withdrawnfrom the precursor component, so that the throughput is reduced withouta “classical defect” occurring.

In addition, the throughput may decrease—without the occurrence of any“classic defects”—if the articles are run, e.g. at too large a distancefrom one another. If the problem of jams or the like occurs at too smalla distance, which results in a stoppage of the installation andtherefore reduces the throughput, a reduction will be given even if thedistance between the articles is too large.

In the above-mentioned cases, too, the inventive approach will beeffective and result in the installation and/or the installation parts(or modules) to be controlled so as to adapt the speeds duringprocessing, to increase or reduce the distance, etc.

In addition, in the description of the embodiments of the invention, thesetting of the speed of the processing was explained primarily by meansof settings of the motors transporting the articles. However, thepresent invention is not limited thereto. Instead of changing theconveying speeds of the motors, other parameters which influence theprocessing speed may be modified. For example, the points in time whenan article from a predecessor component is requested by a successorcomponent may be changed (increased/decreased), for example, within theinstallation and/or between the modules so as to influence theprocessing speed. Likewise, the distance of the articles may be changed(increased/decreased) so as to influence the processing speed.

In addition, the description of the embodiments of the invention hasfurther been based on the assumption that the installation already runsat normal operation. If a job processing is newly started, the job isperformed either repeatedly or for the first time. If the job isperformed repeatedly, the initial value of the desired throughput may bestored along with the job and provided to the installation.

During the restart of the installation for processing a new job, aninitial value of the desired throughput may be missing (in particular ifthe job is performed for the first time). In this case, provision ismade for the initial value of the desired throughput to be eitherpredefined by the job, to be set by an operator, or to be set to adefault value (e.g. zero).

In addition, provision may be made that setting the installationparameters initially comprises performing relatively large steps untilnormal operation is achieved, so as to achieve fast control of theinstallation, after the start, to reach the desired condition. The stepsize may be changed in a linear manner, for example.

While this invention has been described in terms of several embodiments,there are alterations, permutations, and equivalents which fall withinthe scope of this invention. It should also be noted that there are manyalternative ways of implementing the methods and compositions of thepresent invention. It is therefore intended that the following appendedclaims be interpreted as including all such alterations, permutationsand equivalents as fall within the true spirit and scope of the presentinvention.

1. A method of processing articles in a paper-handling installation, thepaper-handling installation being set, on the basis of a jobdescription, to process a predetermined number of articles during apredetermined time period, the method comprising the following beingperformed by the paper-handling installation: (d) detecting the numberof articles being processed by the paper-handling installation duringthe predetermined time period; (e) if the detected number of articles islarger than or equal to the predetermined number of articles: (b.1)increasing the speed at which the articles are processed in at least onesection of the paper-handling installation by a predetermined amount ofincrease, and (b.2) setting the predetermined number of articles equalto the detected number of articles; (f) if the detected number ofarticles is smaller than the predetermined number of articles: (c.1)detecting which of the sections of the paper-handling installation hascaused a reduction in throughput during the predetermined time period,(c.2) determining at least one installation parameter present hereand/or at least one article parameter, and (c.3) on the basis of theparameters determined in (c.2), setting at least one section of thepaper-handling installation and/or reducing the speed at which thearticles are processed in a section of the paper-handling installation,by a predetermined amount of reduction; and e) repeating (a) to (c)while the job is being processed.
 2. The method as claimed in claim 1,wherein (c.3) comprises: determining a deviation of the parametersdetected in (c.2) as compared to parameters detected during a precedingtime period; comparing the deviation to a first predetermined threshold;if the deviation is smaller than the first predetermined threshold,maintaining the setting of the paper-handling installation; and if thedeviation is larger than the first predetermined threshold, setting theat least one installation parameter and/or reducing the speed on thebasis of the parameters determined in (c.2).
 3. The method as claimed inclaim 1, wherein (c.1) comprises determining the number of eventsoccurring during the time period which caused a reduction of thethroughput, (c.3) comprising: determining a deviation of the number ofevents detected in (c.1) as compared to the number of events detected ina preceding time period; comparing the deviation to a secondpredetermined threshold; if the deviation is smaller than the secondpredetermined threshold, maintaining the setting of the paper-handlinginstallation; and if the deviation is larger than the secondpredetermined threshold, setting the at least one installation parameterand/or reducing the speed on the basis of the parameters determined in(c.2).
 4. The method as claimed in claim 1, wherein (b.1) and (c.3)comprise setting the speed such that the speed does not exceed or fallbelow a predetermined maximum speed and a predetermined minimum speed,respectively.
 5. The method as claimed in claim 1, wherein (c.3) furthercomprises taking into account at least one environmental parameter, theat least one environmental parameter being detected during the timeperiod contemplated, or being detected once during a plurality of timeperiods, and taking into account the at least one environmentalparameter in (c.3) comprising reading out optimum installationparameters for the detected environmental parameter from a look-uptable.
 6. The method as claimed in claim 1, wherein (c.3) furthercomprises taking into account any wear and tear in the paper-handlinginstallation, the wear and tear being detected during the time periodcontemplated, or being detected once during a plurality of time periods,and taking into account the wear and tear in (c.3) comprising readingout optimum installation parameters for the detected wear and tear froma look-up table.
 7. The method as claimed in claim 6, wherein adetermination is made, depending on the detected wear and tear of anelement, whether replacement of the element concerned or reduction ofthe speed of the paper-handling installation will provide increasedthroughput of same for the job, wherein (c.3) comprises reducing thespeed if this leads to a higher throughput, and wherein thepaper-handling installation is stopped and the operator is signaled thatthe element is to be replaced if this leads to a higher throughput. 8.The method as claimed in claim 1, wherein (c.2) further comprisesdetecting the number of operators of the paper-handling installation andtheir positions, the capacity utilization of the paper-handlinginstallation being set depending on the number of operators.
 9. Themethod as claimed in claim 1, wherein (b.1) and (c.3) comprise storingthe set speed and the set installation parameters.
 10. The method asclaimed in claim 1, wherein the paper-handling installation processesthe articles in groups, the article parameters further comprising thetotal number of articles within a group.
 11. The method as claimed inclaim 10, wherein each of the groups comprises a predetermined number ofarticles, wherein the predetermined number of articles to be processedduring the predetermined time period is determined in dependence on thesizes of the groups in the job, a value existing for each group whichindicates the average duration of generating a group within theinstallation, and the predetermined number being dependent on thevalues.
 12. The method as claimed in claim 1, wherein the paper-handlinginstallation comprises at least two modules, wherein (b.1) comprisesincreasing the speed in at least one of the modules, and wherein (c.3)comprises setting the installation parameters and/or the speed in atleast one of the modules.
 13. The method as claimed in claim 12, wherein(a) to (c) are performed in a decentralized manner in each of themodules, a central controller monitoring the interface between themodules.
 14. The method as claimed in claim 12, wherein (c.1) comprisesdetermining whether following an increase in the speed, one or moreevents, which caused a reduction of the throughput, occurred (i) inseveral modules in the paper-handling installation, or (ii) only in onemodule of the paper-handling installation, wherein in case (i), (c.3)comprises reducing the speed in some of the modules or in all of themodules of the paper-handling installation, and wherein in case (ii),(c.3) comprises reducing the speed only in the module concerned.
 15. Apaper-handling installation for processing articles which is set on thebasis of a job description so as to process a predetermined number ofarticles during a predetermined time period, comprising: a first sensorfor detecting the number of articles which are processed by thepaper-handling installation during the predetermined time period; asecond sensor for determining at least one installation parameter and/orat least one article parameter; and a control unit effectively connectedto the sensors and configured to, while processing the job, increase thespeed at which the articles are processed in at least one section of thepaper-handling installation, by a predetermined amount of increase, andto set the predetermined number of articles equal to the detected numberof articles if the detected number of articles is larger than or equalto the predetermined number of articles; and detect which of thesections of the paper-handling installation caused, during thepredetermined time period, a reduction of the throughput, and, on thebasis of the parameters present here, to set at least one installationparameter of at least one section of the paper-handling installationand/or to reduce the speed at which the articles are processed in onesection of the paper-handling installation by a predetermined amount ofreduction if the detected number of articles is smaller than thepredetermined number of articles.